This invention provides a combination product useful for improving feed efficiency, growth rate, and carcass quality of pigs. It also provides related growth promotion methods.
Ractopamine and its use as a growth promoter for pigs are disclosed in U.S. Pat No. 4,690,951.
Growth hormone and growth hormone related substances are also recognized growth promoters for pigs. J. Anim. Sci. 35 (4), 794-800 (1972). However, certain disadvantages accompany use of exogenously administered growth hormone and growth hormone related substances. More specifically, the ratio of carcass weight to live weight (dressing percent) is reduced when growth hormone is used. This arises because growth hormone increases rate of viscera growth faster than it increases rate of carcass (muscle, bone, skin, and fat) growth. Further, use of growth hormone causes increased blood sugar and insulin levels which can be detrimental to the health of the pigs.